• Journal of Preventive Medicine and Public Health
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• v.32 no.2
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• pp.177-182
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• 1999

Objectives: To reexamine the association between air pollution and daily mortality in Seoul, Korea using a method of meta-analysis with the data filed for 1991 through 1995. Methods: A separate Poisson regression analysis on each district within the metropolitan area of Seoul was conducted to regress daily death counts on levels of each ambient air pollutant, such as total suspended particulates (TSP), sulfur dioxide $(SO_2)$, and ozone $(O_3)$, controlling for variability in the weather condition. We calculated a weighted mean as a meta-analysis summary of the estimates and its standard error. Results: We found that the p value from each pollutant model to test the homogeneity assumption was small (p<0.01) because of the large disparity among district-specific estimates. Therefore, all results reported here were estimated from the random effect model. Using the weighted mean that we calculated, the mortality at a $100{\mu}g/m^3$ increment in a 3-day moving average of TSP levels was 1.034 (95% Cl 1.009-1.059). The mortality was estimated to increase 6% (95% Cl 3-10%) and 3% (95% Cl 0-6%) with each 50 ppb increase for 9-day moving average of SO2 and 1-hr maximum O3, respectively. Conclusions: Like most of air pollution epidemiologic studies, this meta-analysis cannot avoid fleeing from measurement misclassification since no personal measurement was taken. However, we can expect that a measurement bias be reduced in a district-specific estimate since a monitoring station is hefter representative cf air quality of the matched district. The similar results to those from the previous studios indicated existence of health effect of air pollution at current levels in many industrialized countries, including Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.4
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• pp.315-321
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• 2011

Effects of antioxidant compounds and antioxidant activities of proso millet cultivated in different areas were determined. The cultivated areas were Milyang (plain area of interior), Wonju (mountainous territory) and Sinan (coastal area), and cultivated varieties were Hwanggeumgijang (HGG), Byeoruk-gijang (BRG), Norangchal-gijang (NRG), Bulgeun-gijang (BGG), Whin-gijang (WG). The highest total polyphenol contents of methanolic extracts were 2.54 and 2.65 mg/g in BGG and BRG produced in Sinan, respectively. The highest total flavonoid content were 2.66 and 2.59 mg/g in BGG and BRG produced in Sinan, respectively. The highest total tannin contents were 1.87 and 1.42 mg/g in BRG and NRG produced in Sinan. The DPPH radical-scavenging activity was the highest value of BGG (8.54 mg TE/g) and BRG (8.53 mg TE/g) produced in Sinan. The ABTS radical-scavenging activity was the highest value of BGG and BRG of 19.48 and 19.29 mg TE/g in the grains produced in Sinan, respectively. Generally, there was difference in antioxidant compound contents on the methanolic extracts of proso millet between the cultivated areas and varieties.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.8
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• pp.895-903
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• 2007

As for the increasing demanding on the development of direct-ecological landfill monitoring methods, it is needed for critically defining the condition of landfills and their influence on the environment, quantifying the amount of enzymes and bacteria mainly concerned with biochemical reaction in the landfills. This study was thus conducted to understand the fates of contaminants in association with groundwater quality parameters. For the study, groundwater was seasonally sampled from four closed unsanitary landfills(i.e. Cheonan(C), Wonju(W), Nonsan(N), Pyeongtaek(P) sites) in which microbial diversity was simultaneously obtained by 16S rDNA methods. Subsequently, a number of primer sets were prepared for quantifying the specific gene of representative bacteria and the gene of encoding enzymes dominantly found in the landfills. The relationship between water quality parameters and gene quantification were compared based on correlation factors. Correlation between DSR(Sulfate reduction bacteria) gene and BOD(Biochemical Oxygen Demand) was greater than 0.8 while NSR(Nitrification bacteria-Nitrospira sp.) gene and nitrate were related more than 0.9. A stabilization indicator(BOD/COD) and MTOT(Methane Oxidation bacteria), MCR(Methyl coenzyme M reductase), Dde(Dechloromonas denitrificans) genes were correlated over 0.8, but ferric iron and Fli(Ferribacterium limineticm) gene were at the lowest of 0.7. For MTOT, it was at the highest related at 100% over BOD/COD. In addition, anaerobic genes(i.e., nirS-Nitrite reductase, MCR. Dde, DSR) and DO were also related more than 0.8, which showing anaerobic reactions generally dependant upon DO. As demonstrated in the study, molecular biological investigation and water quality parameters are highly co-linked, so that quantitative real-time PCR could be cooperatively used for assessing landfill stabilization in association with the conventional monitoring parameters.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.67-73
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• 1994

Na-Ca exchange transports calcium ion either into (reverse mode Na-Ca exchange) or out of the cell (forward mode Na-Ca exchange) according to the direction of driving force produced by the changes in ratio of intra- and extra-cellular Na concentrations. Thus, Na-Ca exchange is regarded as the regulator of myocardial contraction. However, the existence of reverse mode Na-Ca exchange and its role in myocardial contraction is still questioned. Present study was performed to identify the presence of reverse mode Na-Ca exchange and its possible involvement in the regulation of myocardial contraction in rat heart. Using the left atria of rat, contraction was induced by electrical field stimulation (EFS, 0.5 msec duration and supramaximal voltage). Changing of the stimulation frequencies from resting 4 Hz to 0.4, 1 or 8 Hz caused typical negative staircase effect in twitch tension, but $^{45}Ca$ uptake showed bimodal increase. When the stimulation frequency was abruptly changed from 4 Hz to 0.4 Hz the atrial twitch tension showed three phased-enhancement, that is, the initial rapid increase (the first phase) followed by rapid decrease (the second phase) and stabilization (the third phase). $^{45}Ca$ uptake was equivalent to tension, i.e. initial significant increase in first 30 second and then decrease. Benzamil treatment abolished the first phase of increase in a dose dependent manner from $10^{-5}\;to\;3{\times}10^{-4}M.$ Bay k 8644 $(3{\times}10^{-5}M)$ treatment enhanced the inotropy induced by frequency reduction and abolished the second and third phase decreases. Benzamil treatment also suppressed the contraction stimulated by Bay K 8644. Although the contraction at 4 Hz stimulation was completely abolished by verapamil $3{\times}10^{-5}\;M$ pretreatment, the contraction reappeared as soon as the stimulation frequency was changed into 0.4 or 1 Hz and interstingly,$^{45}Ca$ uptake were significantly higher than no treatment. From these results, it is concluded that reduction of stimulation frequency causes calcium influx by the reverse mode Na-Ca exchange, resulting in initial rapid increase of twitch tension. then it turns into forward mode exchange to efflux the calcium, resulting in decrease of the twitch tension in left atria of rat.

• Korean Journal of Food Science and Technology
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• v.47 no.5
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• pp.586-592
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• 2015

This study was performed to determine optimum approaches for control of microorganisms in school refectories and kitchens. A reduction of more than 5.0 log CFU/mL was noted for Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Streptococcus mutans after treatment with 5 ppm ozone water for 60 s. Treatment of different vegetables with ozone water for 5 min showed bactericidal effects with 2-4 log reduction of viable cell number; the bactericidal effects differed according to the kinds of vegetables. The viable cell number on kitchen apparatus and tableware was not detected by ozone water treatment for 60 s. In addition, the count of the bacteria floating in the air in refectories and kitchens decreased 2.0 log CFU/1,000 L air to 0-1 CFU/1,000 L air on treatment with 45 ppm ozone gas for 12 hr. Therefore, ozone water and ozone gas may be good candidates as antimicrobial agents that can be used to improve sanitary conditions in school refectories and kitchens.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.128-136
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• 2006

This study was conducted for developing the stability parameter in uncontrolled landfill by using a biomolecular investigation on the microbial community growing through leachate plume. Landfill J(which is in Cheonan) and landfill T(which is in Wonju) were chosen for this study among a total of 244 closed uncontrolled landfills. It addressed the genetic diversity of the microbial community in the leachate by 165 rDNA gene cloning using PCR and compared quantitative analysis of denitrifiers and methanotrophs with the conventional water quality parameters. From the BLAST search, genes of 47.6% in landfill J, and 32.5% in landfill T, respectively, showed more than 97% of the similarity where Proteobacteria phylum was most significantly observed. It showed that the numbers of denitrification genes, i.e. nirS gene and cnorB gene in the J site are 7 and 4 times higher than those in T site, which is well reflecting from a difference of site closure showing 7 and 13 years after being closed, respectively. In addition, the quantitative analysis on methane formation gene showed that J1 spot immediately bordering with the sources has the greatest number of methane formation bacteria, and it was decreased rapidly according to distribute toward the outer boundary of landfill. The comparative investigation between the number of genes, i.e. nirS gene, cnorB gene and MCR gene, md the conventional monitoring parameters, i.e. TOC, $NH_3-N,\;NO_3-N,\;NO_2-N,\;Cl^-$, alkalinity, addressed that more than 99% of the correlation was observed except for the $NO_3-N$. It was concluded that biomolecular investigation was well consistent with the conventional monitoring parameters to interpret their influences and stability made by leachate plume formed in downgradient around the uncontrolled sites.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.232-240
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• 2009

The aim of this study was to determine the processing and reduction factors for ginseng and its commodities during ginseng processing to obtain information of pesticide residue in ginseng. For this study, azoxystrobin was used in two field containing 6 years old ginseng plants. Ginsengs were harvested and processed to obtain different commodities (Dried ginseng, red ginseng and ginseng water and alcohol extracts, red ginseng water and alcohol extracts) for pesticide analysis. The amount of residue levels from wonju and icheon for fresh ginseng were 0.05, $0.03\;mg\;kg^{-1}$ dried ginseng were 0.12, $0.14\;mg\;kg^{-1}$, red ginseng were both $0.05\;mg\;kg^{-1}$, ginseng alcohol extract were 0.28, $0.33\;mg\;kg^{-1}$, ginseng water extract were 0.22, $0.16\;mg\;kg^{-1}$, red ginseng alcohol extract were 0.31, $0.20\;mg\;kg^{-1}$ and red ginseng water extract were 0.09, $0.11\;mg\;kg^{-1}$ respectively. These data were under MRLs notified by KFDA. The processing factors for ginseng products were 3.25, 1.34, 7.84, 4.63, 6.15 and 2.56 respectively. The reduction factors for ginseng products were 1.19, 0.51, 3.41, 1.91, 2.74 and 1.00 respectively. These data showed increment during processing which could be due to concentration but considering water contents, residue levels were similar or decreased than the initial residue level during processing.

• Journal of agricultural medicine and community health
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• v.34 no.3
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• pp.303-315
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• 2009

Objectives: This study, as for activating measures for capable medical physicians to penetrate into the public health sector, is to provide a basic informations which are used for the enlargement of human resources of physicians in the public health sector, by investigating the perception of physicians, who are now working in the public health center, on the training and development of physicians in the public health sector. Methods: The subjects of this study were 126 individuals. The data was analyzed by frequency analysis using SPSS ver. 17.0K. Results: According to the investigation of 'how to support physicians in public health sector', the necessity of almost questions is considered to be important. Especially, regarding to investigation on 'obstacles of physicians' entrance to public health sector', 'relatively low salary' and 'lack of promotion chances' were thought to be considerable. The most significant education programs to work for public health sector is to improve the ability of health administration planning and service performance. Conclusions: The important methods to reinforce and easily obtain the human resources of physicians in public health sector are not only to improve the penetration of physicians to public health sector, but also to enhance the ability of present physicians, even though sufficient recruitment of physicians is essential.

• Journal of the Korea Society of Computer and Information
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• v.19 no.7
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• pp.71-76
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• 2014

There is to be virtually impossible to solve the very large digits of prime number p and q from composite number n=pq using integer factorization in typical public-key cryptosystems, RSA. When the public key e and the composite number n are known but the private key d remains unknown in an asymmetric-key RSA, message decryption is carried out by first obtaining ${\phi}(n)=(p-1)(q-1)=n+1-(p+q)$ and then using a reverse function of $d=e^{-1}(mod{\phi}(n))$. Integer factorization from n to p,q is most widely used to produce ${\phi}(n)$, which has been regarded as mathematically hard. Among various integer factorization methods, the most popularly used is the congruence of squares of $a^2{\equiv}b^2(mod\;n)$, a=(p+q)/2,b=(q-p)/2 which is more commonly used then n/p=q trial division. Despite the availability of a number of congruence of scares methods, however, many of the RSA numbers remain unfactorable. This paper thus proposes an algorithm that directly and immediately obtains ${\phi}(n)$. The proposed algorithm computes $2^k{\beta}_j{\equiv}2^i(mod\;n)$, $0{\leq}i{\leq}{\gamma}-1$, $k=1,2,{\ldots}$ or $2^k{\beta}_j=2{\beta}_j$ for $2^j{\equiv}{\beta}_j(mod\;n)$, $2^{{\gamma}-1}$ < n < $2^{\gamma}$, $j={\gamma}-1,{\gamma},{\gamma}+1$ to obtain the solution. It has been found to be capable of finding an arbitrarily located ${\phi}(n)$ in a range of $n-10{\lfloor}{\sqrt{n}}{\rfloor}$ < ${\phi}(n){\leq}n-2{\lfloor}{\sqrt{n}}{\rfloor}$ much more efficiently than conventional algorithms.

• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.404-410
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• 2014

In this study, we conducted an analysis of the drumming bioacoustics of three woodpeckers typical to South Korea. The targeted species were, from largest to smallest in size, the Black Woodpecker(Dryocopus martius), the Great Spotted Woodpecker(Dendrocopos major) and the Japanese Pygmy Woodpecker(Dendrocopos Kizuki). The drumming sounds of these three species of woodpeckers were recorded and analyzed. Sound recordings were taken in the Guryongsa Valley, Chiaksan National Park and on the campus of Sangji University, Wonju City, South Korea. Drumming recordings were obtained in the following manner. As researchers walked along trails in the investigation areas, when woodpecker drumming sounds were indicated, positive identification of the species was made using binoculars then the recording of the drumming sound was started. The average time per drumming, in seconds, was Black Woodpecker(D. martius) 1.614 seconds, Great Spotted Woodpecker(D. major) 0.683 seconds and Japanese Pygmy woodpecker(D. Kizuki) 0.200 seconds. The average number of strikes for each drumming was Black Woodpecker(D. martius) 31.2 times, Great Spotted Woodpecker(D. major) 14.9 times and Japanese Pygmy Woodpecker(D. Kizuki) 6.7 times. The strike speed, in strikes/sec, for each species was the Black Woodpecker(D. martius)19.3strikes/sec, the Great Spotted Woodpecker(D. major) 21.8strikes/sec and Japanese Pygmy Woodpecker(D. Kizuki)33.3strikes/sec. The frequency of drumming, in Hertz, was Black Woodpecker(D. martius) 776.9Hz, Great Spotted Woodpecker (D. major) 1,213.8Hz and Japanese Pygmy Woodpecker(D. Kizuki) 826.0Hz. In interpreting this data, Analysis of Variance (ANOVA) was used and it was determined that there was a significant statistical difference between species in drumming duration, time and interval of striking. The findings support that the bigger the biomass of the woodpecker, the longer the drumming duration and striking time. However, the smaller the size of the woodpecker, the faster the strike speed. A correlation between body type size and drumming characteristics was clearly identified. As for strike frequency, measured in Hertz, the medium sized Great Spotted Woodpecker's (D. major) frequency was high whereas the Black Woodpecker(D. martius) and Japanese Pygmy Woodpecker's(D. Kizuki) frequency was similar. A clear trend in reference to body size on this measure does not exist.